Search results for "Quiet"

2013

To identify factors limiting performance in multitone intensity discrimination, we presented sequences of five pure tones alternating in level between loud (85 dB SPL) and soft (30, 55, or 80 dB SPL). In the “overall-intensity task”, listeners detected a level increment on all of the five tones. In the “masking task”, the level increment was imposed only on the soft tones, rendering the soft tones targets and loud tones task-irrelevant maskers. Decision weights quantifying the importance of the five tone levels for the decision were estimated using methods of molecular psychophysics. Compatible with previous studies, listeners placed higher weights on the loud tones than on the soft tones i…

Messages beyond the phone: Processing variable message signs while attending hands-free phone calls.

2021

We examined the effects of different types of cognitive distraction coming from a hands-free phone conversation on the processing of information provided by variable message signs (VMS), on driving performance indicators, and on a physiological index of mental effort (heart rate). Participants drove a route in a driving simulator and had to respond to VMS messages under three conditions: no-distraction, visuospatial distraction (attending phone calls with questions inducing visuospatial processing), and conceptual distraction (attending phone calls with questions requiring semantic memory). Results showed more errors responding to VMS messages in the visuospatial distraction condition. In a…

Maturational effects on newborn ERPs measured in the mismatch negativity paradigm.

2003

Abstract The mismatch negativity (MMN) component of event-related potentials (ERPs), a measure of passive change detection, is suggested to develop early in comparison to other ERP components, and an MMN-like response has been measured even from preterm infants. The MMN response in adults is negative in polarity at about 150–200 ms. However, the response measured in a typical MMN paradigm can also be markedly different in newborns, even opposite in polarity. This has been suggested to be related to maturational factors. To verify that suggestion, we measured ERPs of 21 newborns during quiet sleep to rarely occurring deviant tones of 1100 Hz (probability 12%) embedded among repeated standard…

Event‐related brain potentials to change in rapidly presented acoustic stimuli in newborns

1997

Event-related brain potentials of 28 newborns to pitch change were studied during quiet sleep under stimulus conditions that typically elicit mismatch negativity in adults. Rarely occurring deviant tones of 1100 Hz (probability 12%) were embedded among repeated standard tones of 1000 Hz in an oddball-sequence with an interstimulus interval of 425 ms. Two control conditions were also employed: In the first, the 1100-Hz stimulus was presented alone without the intervening standard stimuli, and in the second the deviant stimulus had a pitch of 1300 Hz. In all conditions the infrequent stimulus elicited in most newborns a slow positive deflection peaking at a latency of 250-350 ms. The response…

Temporal loudness weights in background noise: Data and models

2019

Previous studies consistently showed that human listeners primarily consider the beginning of a time-varying sound when judging its overall loudness, and place less weight on subsequent temporal portions. However, all experiments studying this primacy effect in temporal loudness weights presented the target sound in quiet. Here, we compared temporal weights when the target sound was either presented in quiet or in a continuous background noise, and for a variation in the level of the target sound across a range of 60 dB. The target sound was a time-varying narrowband noise, the background noise was a continuous bandpass-filtered noise. In all conditions, we observed the expected primacy eff…

Impact of Nonstationarities on Short Heart Rate Variability Recordings During Obstructive Sleep Apnea

2017

Obstructive sleep apnea (OSA) is a sleep disorder characterized by breathing pauses due to collapse of the upper airways. During OSA the autonomic modulation, as noninvasively assessed through heart period (HP) variability, is altered in a time-varying way even though time-varying properties of HP fluctuations are often disregarded by HP variability studies. We performed a time domain analysis computed over very short epochs corresponding to the sole OSA events explicitly accounting for HP variability nonstationarities. Length-matched epochs were extracted during OSA and quiet sleep (SLEEP) in 13 subjects suffering from OSA (11 males, age 55±11, apnea-hypopnea index 44±19). Mean HP, varianc…

Ventilatory conditioning by self-stimulation in rats: A pilot study

1994

International audience; This article describes an experimental attempt to condition breathing pattern in rats. In this experiment, a freely moving rat was first rewarded by an electrical stimulation of the medial forebrain bundle whenever inspiratory duration (TI) exceeded 300 ms. A bidirectional control was then used: TIs longer than 400 ms were rewarded, and then TIs shorter than 300 ms were rewarded. The frequency of TIs longer than 300 ms increased when this event was rewarded, further increased when TIs above 400 ms were rewarded, and decreased during reversal conditioning (TI < 300 ms). At the beginning of the experiment, stimulation caused increased arousal and motor activity, but af…

Center-to-limb variation of the area covered by magnetic bright points in the quiet Sun

2011

CONTEXT: The quiet Sun magnetic fields produce ubiquitous bright points (BPs) that cover a significant fraction of the solar surface. Their contribution to the total solar irradiance (TSI) is so-far unknown. AIMS: To measure the center-to-limb variation (CLV) of the fraction of solar surface covered by quiet Sun magnetic bright points. The fraction is referred to as 'fraction of covered surface', or FCS. METHODS: Counting of the area covered by BPs in G-band images obtained at various heliocentric angles with the 1-m Swedish Solar Telescope on La Palma. Through restoration, the images are close to the diffraction limit of the instrument (~0.1 arcsec). RESULTS: The FCS is largest at disk cen…

Thomas MacGreevy and Samuel Beckett. Affinity and Controversy

2012

Acquainted with Beckett in (1928) Parisian Ecole Normale, Thomas MacGreevy soon became his confidant and a literary mentor introducing him to James Joyce and Richard Aldington. Their artistic interests took form, among others, of the common declaration “Manifesto. Poetry is Vertical” (1932), signed by them and several other poets associated with Jolas’s transition. However, the intellectual attraction between the two was, at the same time, disturbed, or, so to say, spiced, by the tension between Beckett’s agnosticism and MacGreevy’s Catholicism. Sean Kennedy’s illuminating article (“Beckett Reviewing MacGreevy: A Reconsideration,” in; The Irish University Review, September 2005, pp. 273–288…

Electrophysiological Correlates of Intensity Resolution Under Forward Masking

2010

Nonsimultaneous masking can severely impair auditory intensity resolution, but the effect strongly depends on the stimulus configuration. For example, an intense forward masker causes a pronounced impairment in intensity resolution for standards presented at intermediate levels, but not for standards presented at low and high levels, resulting in a midlevel hump pattern (Zeng et al., Hear Res 55:223-230, 1991). Several aspects of the phenomenon cannot be explained by mechanisms in the auditory periphery. For instance, backward maskers cause midlevel humps at least as large as the humps caused by forward maskers. The present experiment was aimed at studying the relation between the effects o…